Small favours

I am a regular user of Mumsnet and as I need input from other parents, I thought that this would be a good way to get your views.I am completing a Masters in Anthropology and trying to do some research about Reciprocity (responding to a positive action with another positive action, rewarding kind actions, small favours can produce a sense of obligation to a larger (or not) return favours).I am focusing on Play areas and I wonder if you have any stories that could help me. For example, have any of you have made friends with other parents/ carers through taking your little ones to play at the same play area? Even if these relationships dont spill outside the paly areas, is there any aspect of reciprocity while in the pay area? Do adults look for each others children? Do adults exchange advice?Please ladies, any input would be appreciated!!!